码分多址反向链路调度算法与处理时延的关系

研究了码分多址反向链路数据传输采用不同的调度算法受系统处理时延影响的程度，这种影响与信道估计误差有关，也与传输速率的更新时间有关。通过对CDMA2000的动态系统级仿真，其结果显示反向链路上的最大速率与轮询结合的算法、最小路径损耗算法、以及轮询算法在有处理时延时吞吐量性能都会降低，其中最大速率与轮询结合的算法降低的程度最小，轮询算法降低程度最大，最小路径损耗算法介于中间。性能降低也与快衰信道类型相关，信道变化越快算法性能受到的影响越大。提出了一种对调度算法的改进方法，即根据移动台处理时延的变化，为近期处理时延较小的移动台分配更多的资源，结果表明该方法改善了系统吞吐量。

On the relation between scheduling algorithms and processing delay for CDMA reverse link

The degree of impact of system processing delay on different scheduling algorithms for data transmission on CDMA reverse link is studied, which is related to channel estimation error and the update time of transmission rate. Through dynamic system level simulation for CDMA2000, the results show that on the reverse link the throughput performances of maximum rate combined with Round Robin algorithm, minimum pathloss algorithm, and Round Robin algorithm decrease due to processing delay, while the amount of decrease of maximum rate combined with Round Robin algorithm is the smallest, that of Round Robin algorithm is the largest, and that of minimum pathloss algorithm lies between them. The performance degradation is also corresponding to the fast fading type, the faster the variation of the channel, the greater impact on the performances. An improvement method for scheduling algorithms is proposed, which takes advantage of the variations of processing delay, and allocates more resources to those mobile stations with shorter processing delay recently. The results show that the improvement method can enhance system throughput.